Hydrogen peroxide (H2O2) in a water solution has long been recognized as a generally safe antimicrobial agent. However, hydrogen peroxide is thermodynamically unstable and decomposes to form water and oxygen. Consequently, the effectiveness of using hydrogen peroxide as a disinfectant has mixed results and causes hospitals and other medical institutions to resort to chlorine-based bleaches which have environmental and health safety concerns.
Hydrogen peroxide has historically been used in disinfecting topical wounds until researchers proved that it destroyed skin cells, slowed healing and led to scarring. Only very low concentrations of hydrogen peroxide in water solution should be applied topically to wounds but again the stability of the hydrogen peroxide is a concern as well as the residue left afterwards on the wound by surfactants and other chemicals used by chemists in trying to stabilize the very low concentrations of hydrogen peroxide in water.
Hydrogen peroxide is thermodynamically unstable and decomposes to form water and oxygen. Hydrogen peroxide is seen as an environmentally safe alternative to chlorine-based bleaches, as it degrades to form oxygen and water. It can be used for the disinfection of various surfaces and is generally recognized as safe as an antimicrobial agent by the U.S. Food and Drug Administration (FDA). However studies have found that when diluted with regular water, it only retains its efficacy for sterilization for a short amount of time. Hydrogen peroxide decomposes to a low level of residual activity within hours or a couple of days, and proves to be ineffective in certain cases and hospitals and other medical institutions are now being advised to use chlorine-based bleaches for disinfection.
Hydrogen peroxide demonstrates broad-spectrum efficacy against viruses, bacteria, yeasts, and bacterial spores and longer contact times are required for sporicidal activity.
Historically hydrogen peroxide has been used for disinfecting wounds, partly because of its low cost and prompt availability compared to other antiseptics. Only a very low concentration of H2O2 can induce healing, and only if not repeatedly applied. Surgical use can lead to gas embolism formation. Despite this it is still used for wound treatment in many developing countries. It is absorbed by skin upon contact and creates a local capillary embolism that appears as a temporary whitening of the skin.
Owing to the instability of hydrogen peroxide in water, it has become traditional for manufacturer's to put low concentrations of hydrogen peroxide (3%) in opaque bottles, or brown colored glass bottles, to preserve the stability. However, this only works for short periods of time.